1. Field of the Invention
The present invention relates to a solid-state imaging device.
2. Description of the Related Art
There has been proposed an amplification type solid-state imaging device configured to have an amplification function on a pixel-by-pixel basis and perform a readout operation using a scanning circuit, i.e., a CMOS image sensor. The CMOS image sensor has a photoelectric conversion section, an amplification section, a pixel selection section and a reset section which are formed in one pixel, using three MOS transistors in addition to a photodiode making up the photoelectric conversion section (see, for example, the Patent Publication 1). The CMOS image sensor is operable to store electric charges generated by the photoelectric conversion section made up of a photodiode, and, after amplifying the stored electric charges through the amplification section, read out the amplified electric charges using the pixel selection section.
FIG. 1 shows a unit pixel of a conventional CMOS image sensor. In FIG. 1, the reference numeral 5 indicates a photoelectric-conversion photodiode. The reference numerals 101, 102 and 103 indicate an amplification transistor, a reset transistor and a selection transistor, respectively. The reference numerals 13, 11, 12 14 and 114 indicate a signal line, a pixel-selection clock line, a reset clock line, a power supply line, and a reset power supply line, respectively. The unit pixel of the conventional CMOS image sensor has the photodiode and the three MOS transistors in a plane. This means that it is difficult to achieve a high degree of pixel integration.
Patent Document 1: JP 2000-244818A